The HS Code (Harmonized System Code) for polypropylene fabric, which is widely used in a variety of applications due to its durability, resistance to chemicals, and affordability, falls under the category of synthetic textile materials. Typically, for non-woven polypropylene fabric, the HS Code would be 5603. This category encompasses nonwovens of man-made filaments, specifically designed for a wide range of uses from medical applications to packaging and textiles. The exact HS Code can vary depending on the fabric's specific characteristics, including weight, use, and whether it is coated or laminated. For woven polypropylene fabrics, which are used in applications like bags, industrial packaging, and clothing, a different HS Code, such as 5407 or 5402, might be applicable, reflecting their woven nature. It is crucial for businesses to accurately classify their products under the correct HS Code to ensure compliance with international trade regulations and to determine the correct tariffs and taxes.

Vinyl chloride (CH2=CHCl) typically does not react directly with water under normal conditions. This gas, primarily used to make polyvinyl chloride (PVC), a material common in various plastic products, is hydrophobic and does not readily dissolve or chemically interact with water. However, exposure to high temperatures or catalytic conditions can lead to hydrolysis, breaking down into hydrochloric acid (HCl) and other compounds, albeit inefficiently and not of practical relevance. The environmental and health concerns with vinyl chloride relate more to its carcinogenic nature and potential to contaminate water through industrial leakage rather than direct chemical reactions with water.

Polyvinyl chloride, commonly known as PVC, is a popular and versatile synthetic polymer. Its structure is based on the polymerization of vinyl chloride monomers (VCM), resulting in a linear backbone of -CH2-CHCl- repeating units. The presence of the chlorine atom in each repeating unit gives PVC its distinctive properties, such as rigidity, flame resistance, and compatibility with various additives. PVC can be modified into a more flexible form by adding plasticizers, leading to a wide range of applications from rigid piping and window frames to flexible cables and flooring. The structure of PVC can be further modified to improve its heat stability, capacity for blending with other polymers, and processing characteristics, illustrating its adaptability and utility in diverse industrial sectors.